anybody go to 28mm tires, and NOT like the switch?

Discuss light weight issues concerning road bikes & parts.
TobinHatesYou
Posts: 4188
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

Having just started racing this season, primarily on 25s measuring 27mm on my deep wheels, and recently 28s measuring 31mm on my shallow wheels, I can safely say I prefer the wider tires for everything short of perfect tarmac and/or time trial situations. I do not get the "Cadillac" comments at all. The only time wider tires feel like a Cadillac to me are when we're just riding straight in a pack and making slight corrections. I find that stability desirable. Cornering on technical descents? The wider tires are vastly superior. Any minor imperfections in the road? The wider tires soak them up. Big potholes? I snakebite punctured the casing of my 25mm GP5K TL, ending my stage race. I bet the 28mm Mavic Yksion Pro UST would have survived.

by Weenie


jih
Posts: 256
Joined: Fri Jan 29, 2016 12:54 pm

by jih

As a counter-point, I had to take a wheel from support recently - a very rare thing indeed, 17c rim and a 23mm @100psi tyre that actually measured 23mm on the bike.

And, since we were on smooth roads, it was totally fine. Not problematic in any way. For the roads I ride on 90% of the time, would sooner have my 25mm tyres that come up at 27.5mm mounted though.

RocketRacing
Posts: 883
Joined: Thu May 10, 2018 2:43 am

by RocketRacing

I just went from 700x35 to 27.5x2.1 on my gravel bike. I literally have xc tires on it. Love it as it is comfortable (24 or so psi), and likely loses little on the gravel. Sure it is slower on the roads... but that is why i have a road bike.

iamraymond
Posts: 139
Joined: Wed Jun 28, 2017 8:59 am

by iamraymond

A 7 hour ride last week that included a long stretch of rough French pavent convinced me to try 28mm tires. I previously had the 25mm Vittoria Corsas (26.5 measured at 80psi) and I purchased a set of 28mm versions of the same tire. The 28mm Vittoria Corsas measure out to a true 28mm at 60psi. I run them on DT Swiss PRC1400 wheels (18mm internal/25mm external).

I did a short ride during lunch today on a loop I do very regularly and these are my first impressions:
-there was a noticeable increase in comfort. Cracks and bumps seem to be dulled out on the 28mm tires.
-climbing is 100% identical between the 25mm and the 28mm
-descending through corners feels more planted on the 28mm tires
-there's no discernable difference in braking although I haven't really pushed the limits of either tire width
-there's no difference in acceleration, not with my fitness level at least

TobinHatesYou
Posts: 4188
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

jih wrote:
Wed Apr 17, 2019 1:11 pm
As a counter-point, I had to take a wheel from support recently - a very rare thing indeed, 17c rim and a 23mm @100psi tyre that actually measured 23mm on the bike.

And, since we were on smooth roads, it was totally fine. Not problematic in any way. For the roads I ride on 90% of the time, would sooner have my 25mm tyres that come up at 27.5mm mounted though.
Weigh the pros and cons of wide tires. You gain cornering/descending confidence, a significant improvement in comfort and puncture protection (thanks to lower psi.) You lose almost nothing in real world rolling resistance and just a tiny bit in aero drag. Here in NorCal every road race is in the boonies on roads that haven’t been repaved in probably two decades. Even on seemingly perfect roads you sometimes run over detritus or a freshly eroded pothole. I won’t be buying deep rims narrower than 30mm from here on out except for whatever will end up on my future TT bike.

romanmoser
Posts: 310
Joined: Sun May 06, 2018 8:30 pm

by romanmoser

After having tried 25mm tires labelled size ( GP5000TL , GP5000, GP4000S2, Turbo Cotton, Schwalbe Pro One )
28 mm tires labelled size ( GP500 TL )

On clincher disc rims (not into rim carbon clincher, often heavier than the disc ones due to the braking surface)
at least for generic asian rim LB, or Venn, may be different for Schmolke, Bikebeat, Tune.

: - VENN 35 TCD ( 19mm internal 26 26,5mm external width ) updated version is wider but haven't tried them , 400 410 gr measured
: - VENN 507 TCD ( 21mm internal, 28mm external width ) manual lay up, 495gr measured
and finally
: - Light Bicycle 56mm ( 23mm internal, 30 30,5 external width) : 460 gr each measured

My review on rims and 25 vs 28mm tires: not considering tubulars here , other topics thanks
I think both sizes will coexist for a long long time. I am 1 meter 87cm and 65 to 70kg , more of a climber rouleur, spinner , not that powerfull 290 FTP :oops:

I don't have any power meter anymore, but strava, repetitions, cardio etc. They are situations in wich 25mm tires with the VENN rims were better. It was the racier conditions on good to average roads. Including climbing. They measured up to 28 29 mm on theses rims. The 35mm behaved like low profile alus rims box but even calmer. The 507 were very neutral in the winds, they felt like lower rims most of the time maybe except super longs climbs and double digit super hards % short climbs. I tested 25 and 28mm tires on them. The 28mm tires were a bad change in terms of lateral wind catching on the venn rims. Especially on the 507. You definetely could tell these were aero optimized for 25mm tires.

Then 28mm tires on Light Bicycle 56mm rims. The GP5000 TL measured up to 30mm . Pressure max according to conti should be 6,5 . I didn't put them as high. 6 was the highest on good roads and I think it defeat the purpose of wider rims and tires no ? But then again why would you need 30mm tires for road racing, gran fondo, climbing on goods to average roads ? Between 4 and 5,5 depending on the roads, strade bianche, fire roads is the right kind of pressure I think. 28mm tires are more for heavier people or for riding on specifics conditions if racing ( strade bianche, ronde van vlanderen, nova eroica). Ultra endurance long distance cycling ( transcontinental race, trans am bike race) or commuting are where these wheels and tires shine for me... They allow to have more comfort, nearly same average rolling resistance except uphill on good roads, taking more bumps and small potholes if you want it. The grip on the flat and downhill is insane, really. The newer rims 56, 38 mm and 50 mm from light bicycle are optimized for 28mm , the wind on the side makes them a little bit slower than venn 507 but they are better than venn 507 with 28mm tires. They don't have wind turbulences issues between the rim bed and the tire. They are perfect if you think about the 105% rule.

The disadvantages for me for a racier bike set up for criterium, gran fondo , climbing :
- more frontal surface , noticeable above 40 45km/h
- less reactive
- heavier
- tires bouncing around at adapted pressures and feeling " dead "
- I don't like how they behave while climbing and out of the saddle , can't push them, sorry
- Harder to mount on than 25mm tires on narrower rims, but manage to do it by hand horizontally without tire lever

So I think for my disc road bike, I'll have:
- one pair between optimized for 25mm tubeless or latex inner tubes clincher ( 35,38,40,45 max 50mm )
- one other pair optimized for 28mm tubeless tires for long distance brevet, training on bads roads, fast commuting

and maybe a tubular pair ...

I think the rim width range for 25mm tires should be like 17mm to 21mm internal AND 27 28 29 30mm external width.
In that range you have OEM chinese rim ( LB, Farsports, VENN).
Expensiver, a bit lighter and more reactive with the same components spokes hubs according to some friends you have : Bikebeat nice price made in Germany, Schmolke etc.

And then " system wheels " : Campa Bora WTO, Fulcrum 4D, Shimano C40 even if heavier, lower and narrower. With system wheels, you know what you"re buying and often they have very good geometry ( 2:1 rear spokes build, even better for C40, less differential tension between DS and NDS ).

I really like Campa and Fulcrum carbon wheels overall; I wish they were a bit wider but they are the best overall to me. Compared to Roval CLX50 ( average buld, bearings ..)

What are your opinions ?
Thanks

Finx
Posts: 67
Joined: Wed Jun 15, 2016 1:14 am

by Finx

I was having this conversation with a very smart engineer friend of mine.

He suggested the analogy of a shopping cart.

Rolls around great a the smooth tile floor inside the store, but as soon as you take it out to the parking lot, it is a completely different story.

23mm tires are not faster than 25s or 28s on rough surfaces. The rougher the surface the faster the wider tires will be. Going downhill compounds the effect.

There are many other factors that matter.

How much do you and your bike weigh?
How much starting and stopping do you typically do?
How much climbing (vs flats and descending)?
How long are your rides?

What about cornering (at speed)?

I rode 25s at 90 psi for years.

I've recently gone to 28s for road. 32s up to 38s for most gravel roads and rail trails. I have a set of 47s on 650b for the hardcore washboard stuff.

I do a charity ride every year. It's 100 miles with 9500 feet of climbing (I'm a Clyde and not well suited to these types of rides). The year I switched to 28s I was almost an hour faster than my previous best. There were other factors ( smarter pacing, better nutrition), but the 28s were much better me over a long ride with lots of climbing and descending on curvy roads. I had a lot more confidence in them at speed and in turns and could let the bike run more with less braking.

Everyone's experiences are different, but you can't say that 23s are faster without more qualifying details.





RocketRacing
Posts: 883
Joined: Thu May 10, 2018 2:43 am

by RocketRacing

I went from 25c gp4000s to 25c gp5000. Or, i went from a 27mm to 25mm tire (mounted). In other words... it was like i swapped to a 23c Gp4000.

The swap was great and i am very happy. I am also 59kg. I 200lbs rider might better benefit from the 28. The trick is finding the amount of tire YOU need. I need less, and i get some nice aero benefits also, given my rims are just under 28mm wide

robertbb
Posts: 1051
Joined: Thu Jul 23, 2009 3:35 am
Location: Melbourne, Australia

by robertbb

^ And therein lies two truths:

1) What tyres say on the sidewall doesn't necessarily translate to their size or shape when mounted to a specific rim
2) People weigh different, inflate tyres to different pressures, and their riding style/terrain differs

</thread>

Campervan
Posts: 100
Joined: Thu Nov 29, 2018 7:45 pm

by Campervan

robertbb wrote:
Thu Jun 20, 2019 3:41 am
^ And therein lies two truths:

1) What tyres say on the sidewall doesn't necessarily translate to their size or shape when mounted to a specific rim
2) People weigh different, inflate tyres to different pressures, and their riding style/terrain differs

</thread>
I'm weighing 88kg at the moment and finding I was getting punctures in my S-worksclinchers with the latex tubes. I have now put a tubeless S-works 28 on the back with 90psi which I find has dulled the poor road surface and not found any other difference (even when putting down 1000+watts)
BMC Granfondo 02 105
Btwin 540
Specialized Venge Pro Disc

PrimO
Posts: 108
Joined: Thu Nov 20, 2014 8:49 pm

by PrimO

My winter trainer came with 28mm Durano Race-Guards and i didnt like them, they felt sluggish and heavy to me. I changed them for 25mm Lithion 2's which are faster with minimal loss of comfort. I run them with Vittoria latex tubes which helps too.

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TonyM
Posts: 3263
Joined: Thu Jan 22, 2015 4:11 pm

by TonyM

Because of the hype I tried some 28mm but they felt really sluggish! Back to the 23/25 or 25/25.

I suppose that the 28mm are good for heavier riders or really bad roads I suppose.

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ms6073
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Location: Houston, Texas

by ms6073

Commented earlier in the thread about switching from Schwalbe Pro One 28c to 25c tires and now reporting back that I recently gave the 28c gp5000 tubeless tires a go. Initially inflated to 80 psi the tires measured ~28.8mm wide on Nox Falcor 36D (21mm internal) wheels and again the tires felt slow like the 28c Schwalbes, so the next time out, I infalted to 90-psi and while obviously not as plush, the roll feels much better.
Michael - The Anaerobic Threshold is neither...

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pdlpsher1
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Location: CO

by pdlpsher1

90psi on a GP5K 28 on 21C rim is a lot. That's the pressure I use on my tandem with also 21C rims. On my halfbike and with 17C rims I run 75psi front and 80psi rear. I weigh 61kg.

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ms6073
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Location: Houston, Texas

by ms6073

pdlpsher1 wrote:
Thu Jun 20, 2019 4:56 pm
I weigh 61kg.
Back door brag duly noted. :beerchug:
Michael - The Anaerobic Threshold is neither...

by Weenie


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